3v4l.org

run code in 300+ PHP versions simultaneously
<?php list($msec, $sec) = explode(' ', microtime()); echo round($msec*1000) . "\n"; sleep(1); list($msec, $sec) = explode(' ', microtime()); echo round($msec*1000);

preferences:
46.47 ms | 402 KiB | 5 Q